Overdraft and signal printing mechanism for calculating machines



Aug. 18, 1931. F. w. BERNAU 1,819,057

OVBRURAPT D SIGNAL PRINTING BCHANISI FOR CLCULATING ACHINES original med ocr. s1. 1922 1s sheets-sheet 1 :LZJL

Aug. 18, 1931. F. w. BERNAU 1.819.067

OVERDRMPT AND SIGNAL PRINTING NECHANISII PQR CALCULATING MACHINES Original Filed Oct. 31. 1922 13 Sheets-Sheet 2 All@ 18, 1931. F. w. BERNAU 1,819,067

OVERDRAFT AND SIGNAL PRINTING IIECHANISI POR CALCULATING MACHINES Orill Filed Oct. 3l, 1922 13 SheStS-Shet 3 f w. BERNAU 1,819,067 OVERDRAI'T AND SIGNAL PRINTING MECHANISI IOR CALCULATING MACHINES Original Filed Oct. 31, 1922 13 Sheets-Sheet 4 Aug. 18, 1931.

Aug. 18, 1931. F. w. BERNAU OVERDRAFT ,AND SIGNAL PRINTING ECHANISII m CALCULATING IACHINES Original Filed Oct. 31. 1922 13 Sheets-Sheet 5 F. w. BERNAU 1,819,067 OVERDRAP'I AND SIGNAL PRINTING IECHANISII F011 CALCULATING MACHINES Original Filed Oct. 31, 1922 13 Sheets-Sheet 6 Aug. 18, 1931. F. w. BERNAu 1,819,057

OVERDRFT AND SIGNAL PRINTING HECHANISI ma GLULA'I'INGV MACHINES Original Filed Oct. 31, 1922 13 Sheets-Sheet 7 Aug. 18, 1931. F. w. BERNAU OVBRDRAPT AND SIGNAL PRINTING IECHANISI P'Ol GALCULATING MACHINES Original Filed Oct. 31. 1922 13 Sheets-Sheet 8 Aug. 18, 1931. F.1w. BERNAU 1,819,067

OVBRDRAI'T MID SIGNAL PRINTING IECHANISI PDR CALCULATING MACHINES Original Filed Oct. 31. 1922 13 Sheets-Sheet 9 rml; z .Ea/ M Aug. 18, 1931. F. w. BERNAU OVBRDRAFT AND SIGNAL PRINTING NBCHANISI ,0R CALCULATING MACHINES ormnn med oct. :51. 1922 13 Sheets-Sheet 10 Aug. 18, 1931. F. w. BERNAL: 1,819,057

OVERDRA" ND SIGNAL PRINTING ECHNISI fol CALCULTING ACHINES original med ocx. :51. 1922 1s sheets-sheet 11 sponde@ un u m n Aug. 18, 1931. Y F. w` BERNAU 1.819.067

OVERDRAFT AnD SIGNAL PRINTING HECHANIS FOR CALCULATING MACHINES original Filed oct. s1. 1922 1s sheets-sheet 12 Alg- 18, 1931- F. w. BERNAU OVBRDRAFT AND SIGNAL PRINTING ECHNISM POR CLCULTING MACHINES origin/l1 Filed Oct. 31. 1922 13 Sheets-Sheet 13 jmmnw Maij c Oo .0mm N .Q2 UJLIS ao .P34

MOHWNM' t l O M re t i rov e ts be" articu- 1 y P Sen mP em n mg P o 'th bar mechanism being, 1n rmcxgz; that dis- Patented Aug. 18, 1931 UNITED STATES PATENT orrlcs rannnarcx w. aman. or mums, nw mm, assrenoa ro 'anus annuo TYPEWRIm OOIPm, 0I mm m JERSEY man, a conectarlo: or m OVEBDRAIT AID SIGNAL mm@ mi 0B GALGULATUG um Original application fled-October Il, im lerlll le. mi. Divided ald th!! lied mit! b im. .eth1 I0. 7M

chines which are adapted for orming addition and subtraction, and if for listing numbers, and for printing the reun sults of addition and subtraction carried on by the machine.

larly intended for use in connection -w1 the mechanlisns of the zoll known printin ca cu ating mac ine mechanisms set forth in pateilts 'to Hafcolm 15 Ellis No. 1,065,792, June 24, 1913, total signal device; N o. 1,197,276, September 5, 1916, Combined adding machine and writer; and No. 1,203,863, November 7, 910, Mechanical calculator, are described and illusgo trated in connection with so much of these patented machines as will aord a clear understanding of the constructions, operations, functions and principles involved in the invention.

se It is to be understood, however, that the present improvements and the princi les involved therein are not, necessa y, restricted to embodiment in mechanism similar to the Ellis machine as thessimprovements may be used in other calculating machines and the claims are to be understood as covering an improvements involving the principles of e invention in whatever calculating machine they may be employed.

There are certain classes ofwork which a calculating machine is required to handle, demanding notice to the operator that the debit items accumulated exceed the credit items; depositors accounts in a bank constitute a class of work wherein such notitication is important because an account 1n that condition is overdrawn. Furthermore, it is important that a calculating machine not onl signal the fact that an account is overd'rawn but also enable the operator to determine the amount offfthe overdraft and to iprint on the ledger sheet being handled by t e machine the amount the account is overdrawn or the complement of that amount and to so pnrit the gures or identify them that they will be prominently isplayed on the sheet and on carbon copies emo Modern calculating machines, particularly those intended to handle bank and trust computi accounts, are electrically drinn der e control of a starting bar and I have illustrated the prent im rovements in connection with the starting ar mechanism of the Ellis machine. such starting closed in the patent to W. kine, Jr.,

No. 1,136,165, April so, 1915, but it is te be understood that all of the present improvements are adapted for use in connection with manually o rated calculating machines as well as wi motor driven machines.

The signal which is used in connection with the prent invention for the purpose of informing the operator that the account entered is overdrawn, the debitsexseeding the credits, may be individual or duplex. I have described and shown a duplex signal one of the mechanisms of which is to automaticall lockthe starting bar when an over-dra is present in the machine; the other mechanism of the signal lookin the balance or total keys by the use o which the balance or total reprented by the then condition of the accumulator in which the adding and subtracting operations have -been conducted, is shown when the machine is operated.

To insure against any operation of the machine after the itemsv ut into the accumulator and deducted rom it result in an overdraft, the signal may be used in the duplex form, comprising the combination of mechanism which will lock the operating handle or starti bar or operating means, and mechanism w ich will ock the balance or total key but it is to be understood that the invention is not limited to the conjoint use of the two locking mechanisms.

the operator.

Ifnostartingbarlockisueedandtla signal is confined to the locking of the balance or total key, it is still possible for the operator to continue subtracting items although the total of the items subtracted has become greater than the amount of the balance, the operators attention being called to the fact that an overdraft exists only when he starts to take a balance by attempting to depress the total or balance key but the overdraft mechanism having meanwhile operated, the total or balance key is locked and the operator then knows that an overdraft has taken place.

Therefore, When attempt is made to take the balance, and it is found that an overdraft exists, it becomes necessary in order to print the balance, for the operator to manually restore the lock to normal, released, condition in order that the machine may be operated.

To enable this to be done, the locking mechanism is coordinated with the decimal slide of the Ellis machine, such slide being disclosed in Patent No. 1,197 ,276, in such manner that onl operating the slide the lock Will be released so that the o erator can then print the amount of the over raft as set forth in my Patents Nos. 1,508,267 and 1,731,701.

However, inasmuch as an overdraft is an important and abnormal condition, it is desirable that it be printed in a distinguishing manner so that it will be easily picked out by the eye. To that end, my invention provides novel means for printing the item representing an overdraft in a distinguishing fashion, as in a different color, for instance red, and, also, identified by a sign so that the item Will b e marked in a distinguishing manner on any carbon copies, such distinguishing printing occurring on the next operation of the machine after the lock has been released as that operation causes printing of the amount representing the overdraft. The operation of printing an amount representing the overdraft in a distinguishing color may be carried out by employing a biclirome inked ribbon, and ribbon vibrator therefor, and combining therewith novel means which is automatically set so that When the machine operates afterthe release of the lock hereinbefore referred Ito, the ribbon vibrator or shift will be moved for that one operation a sufficient distance to bring the differently colored, say red,- section of the ribbon in line with the printing type so that a red impression will be made when the amount of the overdraft is printed, the mechanism immediately thereafter being restored to its normal condition so that succeeding items will be printed in the usual color.

Identification of an overdraft is accomplished by employing means for automatically printing tlie overdraft with a distinguishing mark or sign. When this means is employed the same overdraft is identified not only on the original ledger sheet but also on allcarbon copies being made.

Identification of an overdraft by printing it with a distinguishin characteristic may, according to my invention, be had by printing the overdraft in a different color, or, accomplished by a sign or signal, or both methods may be used simultaneously.

The Ellis Patent N o. 1,203,863, dated November 7, 1916, provides a subtraction key in addition to the usual controlling keys of the Ellis machine; furthermore, both of the accumulators of the duplex calculator shown in that patent are adapted for the performance of either addition or subtraction.

In the present invention I prefer to have one of the accumulators adapted for both addition and subtraction, as with the accumulators of the machine of the Ellis Patent No. 1,203,863, and to have the other accumulator a straight adding accumulator. The straight adding accumulator may be of the construction set forth in my Patent No. 1,536,757, dated May 5, 1925.

It is to be understood, hoWeyer, that both of the accumulators employed in connection with the present improvements may be adapted for-both addition and subtraction as, for instance, in Ellis Patent No. 1,203,863.

While the subtraction key may be other- Wise arranged, I prefer to substltute it for one of the controlling keys, for instance, the DL subtotal key. Of the other controlling keys of the Ellis machine, the subtotal and total keys may be suitably labeled to represent the total deposits and the balance, respectively, and another of the keys may be labeled to represent the total checks, to particularly adapt the machine for use in bank Work.

As described and shown the subtraction key of the present machine is adapted to become automatically restored after the machine has gone through its cycle of operation, making it necessary for the operator to hold down the subtraction key by the finger if a series of subtracting operations are to be carried on consecutively but as it is a simple matter to provide latching means for holding down the subtraction key, When it is desired to carry on a series of subtracting operations, it is to be understood that such latch may be used. In ordinary bank accounting, it is generally inadvisable to provide means for latching the subtracting key as this opens the Way for forgetfulness on the part of the operator which would result in improper operation in that class of work.

l Combined withY the subtracting keyis special mechanism, substituted for certain of the pieces, cams, and levers of the machine of Ellis Patent N o. 1,203,863 and, additional thereto, a link and a special hook or pawl bg which the parts are conditionedso that t eaccumulator is brought into a condition by which it will rform subtraction on the next operation o the machine. Itis to be understood that the foregoing mechanism does not interfere with the carrying on of addition in the straight adding accumulator as, if both adding and subtracting accumulator and straight adding accumulator are employed, subtraction can be carried on in one accumulator while addition is being performed in the other accumulator. Furthermore, a total can be taken from one accumulator, the amount of which ma be subtracted from the accumulation o the remaining accumulator.

This special mechanism which is used in connection with the subtracting keyl is set forth and claimed in another app ication which is a division of m Patent No. 1,731,- 701 dated October 15, 1529.

If the resent improvements are provided i in an El is machine of the class employing lock or locks or signal or signa an automatic tabulating mechanism for shifting the carriage from one tabulated position to another, it becomes necessary to prevent automatic tabulation occiirring-on the next operation of the machine after an overdraft has occurred. Mechanism is provided which, when the decimal slide is moved from its usual position for the purpose of setting the parts so that the machine may be released and the overdraft printed, causes the automatic tabulatin mechanism to be rendered inoperative an to remain so the decimal slide is restored to normal position.

This tabulating mechanism is aet forth and claimed in another ap lication which is a division of my Patent o. 1,731,701.

The overdraft mechanism b which the kretofore referred to are operated and other mechanisms are set, is under the control of the subtracting pawl or hook of the highest order ofthe adding and subtracting accumulator. The subtracting pawl or hook itself is of the same construction as the corresponding device of the Ellis Patent No. 1,203,863. Combined with this subtracting pawl or hook and with the shift bar of the adding and subtracting accumulator, is an overdraft lock latch by means of which an overdraft condition results in such a setting of the overdraft lock latch that the overdraft mechanisms hereinbefore referred to are operated to lock the operating means, such as the starting bar, and, also, the balance or total keys if duplex, combined, locking means is employed.

In Patent No. 1,508,267, dated September 9, 1924, I have claimed the automatic lockinr of the total and sub-total keys by a certain part of the mechanism hereinafter set forth. In another application which is a division of in Patent o. 1,731,701, I have set forth an claimed the mechanism for automatically locking the starting bar when anoverdraft occurs.' I

The resent improvements being additional to mechanism of the Ellis machine reference is to be had to the aforementioned Ellis patents for a full disclosure of all mechanisms-and their operations which are directly or indirectly related to the said improvements. In the following description and accom ying drawings reference is made to on y so much of the patented Ellis machine as will'ail'ord a clear Iunderstanding of the relationship of the present improvements thereto.

I am aware that modifications may be resorted t in carrying ont the essential principles of the various improvements hereinbefore outlined and which are hereinafter specifically described and are shown in the accompanying drawings. It is to be understood, therefore, that the constructions specifically described and shown, while the preferred embodiments of the invention as at present devised by me, are susceptible of modification in many res ts without deprting from the essentia principles thereo In the accompanying drawings:

Figure 1 is an elevation of the left-hand side of the machine, showing only so much of the mechanisms of the patented Ellis machine as will aord a clear understandmi; of how the resent improvements are re ated to the su tracting ke mechanism for controlling the upper ad ing and subtracting accumulator, and the overdraft locksvfor the balance and total deposits keys or total and sub-total keys, the subtracting key being in depressed position and the mechanisms controlled thereby in their set condition;

Fi 2 is a similar view, the total or balance ey and the sub-total or total deposits keys being locked by the overdraft mechanism, an overdraft having previously occurred, the subtraction key being in normal position;

Fig. 3 is an elevation at the right hand side of the machine, a number of mechanisms being omitted for the sake of clearness, showing certain parts of the hand tabulation and automatic tabulation mechanisms, the set link for the overdraft mechanism, end of decimal slide, and certain restoring mechanisms, the parts being in normal position and the tabulating hook in position to perform automatic tabulation;

Fig. 4 is a perspective view, the side or sub-total key, the ribbon shifting mechanism and decimal slide, various mechanisms of the machine being omitted for the sake of clearness, the overdraft mechanism and locks being in normal position;

Fig. 5 is a detail view of the startin bar mechanism, showing the overdraft loc in locked position;

Fig. 6 is a plan View at the right hand side of the machine, a number of mechanisms being omitted for4 the sake of clearness, showing certain parts of the tabulating mechanisms, and the set link for the overdraft mechanism, the decimal slide being in its right hand position, and the tabulating hook in position to perform automatic tabulation;

Fig. 7 is an elevation at the right hand side of the machine, a number of mechanisms being omitted for the sake of clearness, showing certain parts of the tabulating mechanism, the set link for the over'- draft mechanism, end of decimal slide, and certain restoring mechanisms, the set link having been moved to the right by the manipulation of the decimal slide, the tabulating hook being in normal position, and the tabulating control lever being in position to prevent automatic tabulation;

Fig. 8 is a view like Fig. 7, the tabulating hook having risen and being prevented from operating the tabulating mechanism by the control lever, the parts being as they appear at the end of the forward stroke of the operating shaft;

Fig. 9 is a plan view of the parts when in theJ position shown in Fig. 7;

Fig. 10 is a part side elevation and part sectional view showing certain of the mechanisms at the right hand side of the machine and, also, the overdraft mechanism at the left hand side of the machine, the shift bar of the accumulator being set for addition and the overdraft mechanism and starting bar overdraft lock and ribbon mechanism being in normal position;

F ig. 11 is a rear elevation of the machine showing the overdraft sha-ft and certain of the devices related thereto;

Fig. 12 is a plan View of the overdraft mechanism, ribbon mechanism and links or bars that control the locks, the decimal slide being shown as having been moved toward the left, the front part of the machine and various mechanisms being omitted',

Fig. 13 is a partly sectional, partly elevational, detail view of the overdraft mechanism as set for carrying on a subtracting operation, before an overdraft has taken place;

Fig. 14 is a similar view showing the position of the parts after an overdraft has occurred;

Fig. 15 is a detail side elevation of the ribbon shift mechanism when in normal position for causing ordinary printing, say in black, to occur;

Fig. 16 is a similar view showing the mechanism arranged so that the ribbon vibrator will be shifted to cause printing in a distinctive color, say red, as when an overdraft has taken place;

Fig. 17 is a front view of the decimal slide shown in its extreme right hand position;

Fig. 18 is a. side elevation of mechanism for automatically printing identifying signs or signals, the parts being in normal position Fig. 19 is a similar view, the parts being in position to print a subtracting sign;

Big. 20 is a similar view, the parts being in position to print a credit balance sign, or an overdraft;

Fig. 21 is a detail side elevation of certain of the parts of the mechanism of Figs. 18,

Figi 22 is a detail view of a link shown in Figs. 18, 19, 20; and

Figs. 23 and 24 are views illustrating samples of the printed record.

As set forth in Ellis Patents N o. 1,197,276 and No. 1,203,863, the machine is driven or operated, either by a handle, or by an electric drive, neither of which is shown, from a shaft O1. In the accompanying drawings only so much of the patented Ellis machine is shown as will afford a clear understanding of the relation of the present improvements thereto. Modern calculating machines, particularly those intended for loose leaf led er work, are electrically driven and control ed by a starting bar. I have, therefore, illustrated starting bar mechanism for the control of the electric drive such mechanism appearing in Figs. 4, 5, 10 and 12.

The shaft 01 carries a piece M051 (Fig. 3) which is operated by the electric drive.

Secured to shaft P1 which is mounted in the frame and in the side plate P50 of the printing section is a crank 0160 which is operated from the piece M051 by the printing pitman O61. Carried by the shaft P1 is the paper feed lever P74.

Referring to Figs. 3, 4, 6, 7, 8, 9, 18, 19, 20, the signal setting arm which is moved by the cams NGTR and 67NR that swing the frames of the wheels of the accumulators, as shown in Ellis Patent No. 1,065,792, appears at (30P. One of the printing type sectors is shown at P54, pivoted to arm 52P at P10 and adapted to be set by link P53; the signal 65P which is pivoted to arm P52 at P10, is operated by link 23.55 by improved means hereinafter described, of which the signual lever 61P pivoted at P10P constitutes a part.

The decimal slide P67 is operated by a slide B53 connected to the hook P68 of the slide P67. The piece B53 has a button 10B and is movable over the scale B154. The

' tracting accumulator.

ysub-total kev K67 of the lower acc amano? decimal slide P67 7, s 9, 1o, 12. V e

'Ihe lever P272 (Figs 3, 4, :bis 12) controls the automatic turmng'of n.

A plate D50 which is secured to hand end of the operating shaft 01 (Figs. 1, 2) affords the means by which motion of said shaft is utilized for the operation of the accumulators, according to the controls eilected by the various controlling uch of the present improvemeutsfasre late to the controlling keys, includ'uig the subtracting key K67, the balance on total ke K63 for the upper accumulator, and the sull-total key or total deposits key mi are shown more particularly in Figs. 1, 2, 4.

The lower accumulator is not shown in detail. This accumulator is combined with the mechanisms of Figs. 1 and 2, is controlled only for purposes of addition and will be construct as set forth in my Patent No. 1,536,757 dated May 5, 1925. It ls to be understood, however, that the lower accumulator may be a combined adding and subtracting accumulator as disclosed in Ellis Patent No. 1,203,863 as additional mechanism could be employed so that subtraction as well as addition could be carried on in the lower accumulator in connection with the overdraft features of the present invention. A.

Only so much of the upper combined adding and subtracting accumulator is shown in Figs. 4, 10, 11 12 as will @ford a clear understanding ci the o ration of the mechanisms when an over rafttakes place, and the relationship of this accumulator to the improved mechanism in Figs. 1 and 2 by which the upper accumulator is controlled. Reference into y to Ellis Patent No. 1,203,863 for a d y disclosure of the general construction and principle of the upper adding and sub- The subtraction key and subtracting mechanism.-The key used for setting the machine so that subtraction may be. performed in the upper accumulator is chown at K67 (Figs. '1 and Qthis key in tituted for the r. ungxlator of the Ellis Patent No. 1,197,276. Itis not essential, however, that the Dr. subtotal key of the lower accumulator be with. A latch L160 which is actuad by spring 81L and is pivoted at L20 is ,p pted to latch the subtraction key X67? when the latter is in depressed tion. Plvotally connected to the latch 160 at L23L is a lo set link 64L which is provided at N18 wit a pin amv is provided at X with fa cam slot so fashioned and located that the set link is normally sustained in the ff tion shown in Fig. 2 by a screw pin 17 prothe present instance, su

left the 'cam lever 60L is also frame B47and on which said set hnkreata. When the subtraction key K6? is depressed, however, the movement ofthe set link ML to the lett, camel which thereupon allows the eet link to drop to the podtxon shown in F' 1. The shafts Nl'an 1N carry the cams 67B and 67H3 (FIS. 18, 19, 203 which swing the wheels of e upper an lower accumulatore into and out of engagement with the adding' racks or actuators, as' lained in Ellis Patent No. 1,208,863, an carry on their held in its engaged and 1; 1. relation to the adding racks.

o AsshowninFi .4,10,12,13 14,the irregular shaped 'ft be Neo i Patent No. 1,203,863 is em loyed and on the left hand end of this r there is secured a crank lever 69N which has a square stud D13 at its lower end and a stud N19 at its upper end. S ring 82N normally pulls the crank lever N in a counter-clockwise direction.

A subtracting oplerating hook 68N has a slot 68Nb whic it is slidably mounted on the pin 19. This hook is normally drawn rearwardly on the pin N19 by two contractile coil springs N81 located on 'o psite sides thereof and connected to pin N19 and to a pin 17N on thehook. One of the srxngs N81 is obscured by the hook 68N1n igs1and2. AeoilspringN82 which 1s connected to one of the pins 17N and to the subtracting detent N69, serves the double purpose of tending te draw the subtracting operating hook 68N downward- 1y naund the subtracting datent N69 upwa again to Figs. 1 and 2, there is iv on a screw L25L a sub cam 162which has a cam at its ht hand end with which the pin L22L on latch L160 ,f .e the said pin riding 0n ,o face and dsp said cam L162 when the subtracting key 1s de, p as shown in Fig. 1. A subtracting ivoted on the screw L25L and is conn to the subtracting cam L162 by a `contractile ssrin L80 which normally holds the left han en of the subtracting cam lever 60L raised and in contact with a headed stud L16L on the subtracting cam L 162.

A total cam lievery 58L is pivoted on screw mLandhasitslefthandendabutting screw pin N17toentcrthecamslotX' a pin L21L projecting from the subtracting cam L162. The normal position of the total cam lever 58L is maintained by the engagement of the right hand cam notch thereof with pin L14L carried by the latch 56L for the sub-total or total de osits key K64, such latch and key being o the same general construction set forth in Ellis Patent N o. 1,197 ,276. A spring 56L normally draws the upper end of the latch 56L against the stem of key K64 so that when the keyis depressed the latch Will engage the notch thereof.

A hardened shoe L90 is secured by rivets 28D to the left hand end of the subtracting cam lever 60L for cooperation, when set by the keys K63, K64 and K67, with the hardened shoe D90 on the lower end of iying lever D53 which is ivotally mounted on the plate D50 and 14 and adapted to cooperate with the square studs D12, and 13D on said plate.

A. total pawl L62 is pivoted on a stud 19L carried on the inner face of the subtracting cam L162, said total pawl having a pin 20L which extends underneath the subtracting cam L162. The total pawl L62 is normally held with the pin 20L abutting the lower edge of subtracting cam L162 by the action of a springl L82 connecting said total pawl to a projecting part of the subtracting cam L162. The total pawl L62 carries on its upper end a hardened shoe L91 secured by rivets 28D.

The total or balance key K63, is held, when depressed, by a latch L56 which is ivoted at L19L and is provided with a pin 21 adapted to be drawn against the end of the total cam 58L by the action of spring L56a when the key K63 is depressed.

Setting the accumulator by subtraction keg/. Vhen the subtraction key K67 is depressed, it is immediately latched in its depressed position by the latch L16() 'whose operation results in parts assuming the positions shown in Fig. 1. The riding of the pin L22L on the subtracting cam L162 causes the whole system of mechanism associated with L162 to turn in a general clockwise direction, resulting in the total cam lever 58L becoming released from the pin L21L, the subtracting cam lever 60L to rise so that its shoe L90 is against the shoe D90 of the iiying lever D53, and the total pawl L62 to become elevated so that it will be engaged by the shoe D90 at the end of the prward stroke of the shaft 01 and plate The movement of the latch L160 causes the set link 64L to shift toward the left, thereby allowing the screw guide pin N17 to enter the cam slot X. This results in the set link 64L dropping from the position shown in Fig. 2 to that shown in Fig. 1. Normally the lower edge of the subtracting operating hook 68N rests on the pin N18 so that said subtracting operating hook is held in Ielevated position. When, however, the set link 64L descends, as described, the suhtracting operating hook 68N is allowed to drop so that it is positioned for engagement by a pin 18N on the crank 65N which turns thecams (not shown) that lower the wheels N50 (Figs. 4, 10, 13, 14) into engagement with the adding racks of the machine at the pro er time. The subtracting operating hoo 68N is, by the movement of the set link 64L, thus conditioned so that it may he. pulled toward the right when the crank 65N swings to -the right.

Subtractz'ng operation-The parts having thus been set, when the machine is operated. either by a handle or electric drive used for the purpose of turning shaft 01, the plate D50 which is normally in the position shown in Fig. 1 is turned to the right and then reverses its motion and resumes the position shown in Fig. 1. Before the return of the plate D50 to the normal position of Fig. l, the subtraction key K67 becomes restored and the subtracting cam L162 and subtracting cam lever GOL and total cam lever 581,. all resume their normal positions.

In the Ellis machine sct forth in Patents No. 1,197,276 and No. 1,203,863 when an operation of addition is to be performed, the adding racks or actuators R50 (Figs. 125, 14) advance, during the operation of the machine, as far as allowed by the setting of the numeral keys before the shafts N1, 1N. are turned (according to which accumulator is being used) for the purpose of engaging the wheels N50 (Figs, 4, 10, 13, 14) with said racks. This action occurs, in an adding operation, when the plate D50 has moved through an angle of about 45. The wheels N50 remain in engagement with the racks R50 until the racks have returned to normal position, such return of the racks turning theadding wheels N50 according to the extent of travel of said racks.

When an operation of subtraction is to be performed, however, as the number is to be immediately deducted from any number set up on the wheels N50 during a previous operation of the machine, it becomes necessar to cause the wheels N50 to engage the rac s R50 before said racks move and to disengage the wheels N50 from the racks before the racks start to return to their nori mal position. In a subtracting operation, therefore, it is necessary to move the upper crank 65N to the right from the position shown in Fig. 1 beforethe racks R50 have started to move.

The subtraction key having been set and the parts being in the position shown in Fig. 1, when the machine is operated, the swinging of the plate D50 in a clockwise direction results in a temporary arrest of the flying lever D53 because its lower end is tcmporarily blocked by the shoe L90 on the subtractto be turned and the frame ing cam lever 60L. This results in` lever D53 pulling upon link D56 which connects it to the crank 65N of the adding and subtracting accumulator, causing the shaft N1 N 56N, which carries the shaft N2 to be moved and 'been N then mesh with the racks R50 before the racks start to move. The roller A30 on crank 65N is drawn into the notches 170A so that the wheels N50 are retained in engage ment with the racks R50. The movement of the connecting link D56 to the right from the position shown in Fig. 1 also results in the pin 18N pulling upon the subtraction` operating hook 68N which, throug?.e the s ring connections N81, pulls upon t pm V 19 and thus turns the crank 69N and the shift bar N90, bringing the shift bar to the position shown in Fig. 13, whh is the subtracting position. The first art of the movement of the plate D50 re eases the restoring lever D67, allowing the spring N82 to snap the Subtracting detent N69 upwardly so that the notch N 69 thereof engages the squalo` stud D13n on crank 69N. l

During its clockwise movement, thclate D50 drags the lower end of flying lever D53 ast the shoe L90 on the subtr cam ever 60L so that after the accumulator has been set for subtraction and the wheels` N50 engaged with thc racks R50, the said dying ever D53 simpl turns idly on its pivot D14 and exerts no urther action on the crank N and hook 68N. The lower en d the lever D53 is finally drawn across theshoe L91 of the total pawl L62 and as this paw] is actuated by spring L82, it is slightl deressed, allowing the flylng lever D to gnally abut the shoe L91.

On the return stroke of the shaft 01 the plate D50 is turned in a counter-clockwise irection. The return movement of `they V late D50` causes the lower end of leverD'f to press against the shoe L91 of the total awl 62. The pressure bein almost in adlarect line with the pivot 19 of the total pawl L62, i. e., almost directly on a dead center, there is no tendency for the lev'ervDBto depress the total pawl L62 but, on thecontrary, the total pawl L62 constitutes a solid abutment to temporarily resist the retulgp of the lever D53 so that pressure is applied through lever D53 and connecting li JD56 to the crank 65N, causing said crank to be returned to its'n'ormal position at the o r ning of the return stroke of the plate .n 0, thereby resulting in the turning of sha l and the raising of the frame 51N, 56N,`anl disengagement of the wheels N50 from the racks R50 before the racks start to return to normal position. When the plate D50 returns to its normal position, it enqter-clockwise direction.

y the restoring"level"- D67 and causes e 1n D13D to elevate the right hand end subtracting detent N69 and to withdraw it D13.

While no disclosure is given of means for latching down the subtraction key H67 for a series of repeated eubtractions without requiring the operator to hold his finger o n said key such latching means may be provided, if desired. In the construction disclosed, the subtraction key K67 will instantly rise when the latch L160 is moved in a coun- This action automatically occurs on the return stroke of the shaft 01 and late D50.

Means, au as set forth in my Patent No. 1,731,701 may be provided for automatically releasi the latc es 67L, 68L, L160 for the keys K X64, K67 on the return stroke of the plate D50; and means for releasing them by depressing the error key, may be used, as disclosed in that ap licaton.

vreleasin movement o the latch L160 in a counter ockwise direction by means such as previously explained causes the set link 64L to be drawn toward the right, out of the position shown in Fig. 1, where'u the cam edges of the slot X cause the set -nk to ride on the pin N17 and resume its normal position shown in Fig. 2. The rising of the set link 64L causes its in N18 to elevate the subtracting hook GBBlJfrom the sub tracting 'tion to the "adding position of Fig. 2 wm it will remain as long as the subtraction key K6? sition so that addition may be perfume the upper accumulator by de ressing the proper controlling key provid in the Ellis machine.

When the plate D50 assumes its normal ositiom, itsen agement withv the restoring ever D67 resu ts in .disengagement of the detent N69from the lever 69N and the shift ball then returns to the adding position shown in Fig. 10.

When it is desired to subtract a series of items, the subtrgctiign, key isf tlleld in depressed position y efngero eo rater, the subtracting cam L162 and the sillltracb ing cam lever GOL then remaining in the position shown in Fig'. 1 by reason of the cooperation of pin L22L of latch L160 with subtracting cam L162. When the subtracting key is thus held down, at a time just prior tothe plate D50 assuming its normal position on the return stroke, the lower end of the flying lever D53 strikes the upper side of the shoe L90 on the subtracting cam lever GOL but as the left hand end of said lever is held in raised vposition by spring L80, the return of the dying lever D53 to normal position merely slightly dep1 c the left" hand end of cam lever 60 from engagement with the stud.

remains in elevated 

